I like simple, especially if it works. If you have the tools, cut a couple of pieces of plywood, and glue them together to form a single piece (that is twice as thick). Lay out your holes and drill their centers with a small diameter drill. On the bottom use the small hole to center the tip of a spade bit that is large enough to make a shallow counterbore that is a little deeper than the thickness of an installed T nut. Then drill the holes from the top to a size that leaves a little room for alignment. Using the press an an alignment fixture, with taped washers to protect its finish, install the T nuts, then remove the press from the wood and use something like a deep socket and a mallet to finish seating the T nuts. This plate can be used at home or at the range, in conjunction with whatever clamps that you like. Of course you will want to use bolts that are of such a length as to not protrude any farther than the T nuts. When it is finished, you have the option of using a router to round the top corners (except where they lend support to the press), sanding, and applying some sort of finish....or not.
